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Chapter 2
CIP Services and User-created Tags
56
Rockwell Automation Publication 1756-PM020F-EN-P - January 2019
Message Reply Field
Bytes
Description
Reserved
00
General Status
00
Success
Extended Status Size
00
No Extended Status
Reply Data
00 00
C2 00
00 00 00 00
Member 1 info, type, offset:
non-array (0000)
SINT (00C2)
Offset (00000000)
00 00
C1 00
00 00 00 00
Member 2 info, type, offset:
bit 0 (0000)
BOOL (00C1)
Offset (00000000) (bit 0 in the previous SINT)
0C 00
C3 20
04 00 00 00
Member 3 info, type, offset:
12 element array (000c)
INT (C3 20)
Offset (00000004)
00 00
CA 00
1C 00 00 00
Member 4 info, type, offset:
non-array (0000)
REAL (00CA)
Offset (0000001C)
53 54 52 55 43 54 5F 42
3B 6E 45 42 45 43 45 41 48 41
00
Template Name (STRUCT_B)
The structure name precedes the 0x3B in the stream of bytes. All remaining bytes are
outside the scope of this document.
5A 5A 5A 5A 5A 5A 5A 5A 5A 5A
53 54 52 55 43 54 5F 42 30 00
Member 1 Name: The Logix Designer application selects the name of the member for
one or more members. The host member for the BOOL (Member 2) follows.
Member 1
is sent on the wire but is not visible to the user in the Logix Designer application Data
Monitor view. As indicated by the offset value for Member 3, three bytes of pad are
inserted after the SINT for this host member, for data alignment. When reading or
writing the structure, the pad bytes are sent on the wire.
70 69 6C 6F 74 5F 6F 6E 00
Member 2 Name is the first member of the structure that is visible to the user in the
Logix Designer application Data Monitor view. This is the
pilot_on
member. The
Member 2 information from earlier in the packet indicates this is a BOOL type and the
data offset is zero. The client identifies that the BOOL is part of the Member_1 at the
zero data offset, and that this is bit 0 of that member. The other 7 bits of Member_1
are not used and are not visible. Member 2 is not sent separately on the wire because
it is part of Member_1.
68 6F 75 72 6C 79 43 6F 75 6E
74 00
Member 3 Name: This is the
hourlyCount
member.
It is a DINT data type and is at offset 4.
72 61 74 65 00
Member 4 Name: This is the
rate
member. It is a REAL data type and is at offset 1C.
The user-defined data type (UDT) Template Name string and structure
member names, stored as null-terminated strings follow the member
information. For a UDT structure, the Template Name string contains the
Template Name followed by the characters
;n
plus additional characters. This
may also apply for some non-UDT structures. For other non-UDT structures,
the semi-colon may be followed by other characters, or just a NULL instead
of the semi-colon and characters. Non-UDT structures are beyond the scope
of this publication and should not be accessed as whole structures.